Manufacturing a precision optical link between two optical components is typically complex and expensive. For example, the alignment of an optical fiber and an optical die (laser diode, photo diode) is crucial and requires significant precision.
It is common industry practice to mount an optical die with its active layer (the plane of the wafer) parallel to a carrier such as a PCB or glass plate. The optical axis is then perpendicular to the surface of the carrier or circuit board. In many cases it is practical to orient the axis of the fiber parallel to the surface of the carrier or circuit board, in which case it becomes necessary to redirect the light by means of, for example, a mirror combined with a lens. Thus, conventional coupling schemes involve a perpendicular arrangement of the optical axes of the fiber and die and use of a mirror to redirect the light normally in combination with a lens or multiple lenses.
The requirement for a mirror and lens also arises from the scenario in which an optical die such as a photodiode is to be mounted on a circuit board that already has existing traces defined such that the optical fiber requires precise alignment with the circuit board. In order to achieve the optical link in this scenario, the light beam emitted from the fiber must be bent so that beam is perpendicular to the circuit board. Further, some distance must be allowed for light propagation, which also requires the use of a lens for focusing.
Applicants recognize a need for a low cost and mass producible apparatus and associated manufacturing process facilitating precise alignment of optical components such as an optical fiber and an optical die.